Information storage applications continue to grow at a rapid rate due to the successful development of business and consumer products for processing data, video, and audio signals. Most notably, with the explosion of personal computer systems in the workplace, there exists a great need for storing digital data. Digital data is discrete in time and level and is typically stored in the form of binary 1's and 0's. Advances in digital storage products have mostly been limited to three key storage technologies: semiconductors (e.g., ROMs, RAMs, PROMs, "flash" EPROMs, etc.), magnetic recording systems (e.g., tapes, flexible disks, hard disks, etc.), and more recently to optical recording systems (e.g., tape cartridges, CD ROMs, laser disks, magneto-optical disks, etc.). Competing storage technologies have been all but eliminated due to the consequent and steady reductions in the price of semiconductor, magnetic, and optical storage systems.
Presently, optical recording systems enjoy great commercial appeal because of their high storage capacity, cost effectiveness, and reduced susceptibility to noise and data corruption. Optical recording systems are ideal for storing vast amounts of data on a permanent or long term basis. Furthermore, the advent of Write-Once-Read-Many (WORM) technology offers added flexibility and versatility for optical recording systems. WORM technology allows an optical medium to be repeatedly erased and written to many times over. In other words, old, useless data stored on an optical medium can now be erased and new data written in replacement thereof.
Typically, optical recording systems employ a laser or some other form of light source to "read" and "write" data from/to an optical medium. In a "write" operation, the light is directed by means of a lens assembly and focused onto the optical medium. The focused light causes a characteristic of the optical medium to become altered. The optical medium retains the altered characteristic, even after the light source has been removed. By pulsing the laser over various, designated portions of the media, digital data can be "written" and stored onto those portions. Later, the data can be retrieved by directing the light to the portion of the media containing the desired data. The data is "read" from the medium by detecting the signal contained in the light reflected off the media.
However, one common problem shared by virtually all optical recording systems is that of particle contaminants. Particle contaminants, such as dust, enter optical recording systems through various openings in the housing. One way in which particles typically enter is through the opening used to enter and remove the optical media. Sometimes, particles are also introduced into the device through the air vents. Due to the excessive heat generated by the internal circuits and power supply, open air vents are provided for cooling. In many cases, fans are used to circulate surrounding air within the optical recording system. Otherwise, the lifespan of the optical recording system would be greatly retarded. Furthermore, in certain types of optical recording systems, such as magneto-optical disk drives, it is highly desirous to keep the temperature constant, as the read/write process is temperature dependent.
Once these particles invade the interior of an optical recording system, they oftentimes settle onto sensitive components. Some of the components most susceptible to particle contamination are those of the lens assembly and, particularly, the focusing lens. Dust particles which settle on the lens used to collimate the light, the beam splitters, the mirror, and the focusing lens, interfere with the light beam used to read and write data. The direct result is an increase in the amount of noise in the signals during read/write operations. Increased noise significantly degrades the overall performance of the optical recording system because it introduces errors.
Additional circuits can be implemented to compensate for the particle contaminants. The disadvantage with additional circuits is that the circuits add to the complexity of the system and increase costs. Moreover, these additional compensation circuits would eventually be overwhelmed as more and more dust particles settle on the various components.
Furthermore, some of the particles settle on the rails and bearings used to physically move the lens to the correct track during seek operations. This could have dire consequences. These dust particles might interfere with the seek operation to cause the wrong track to be accessed. If the wrong track were accessed, the drive will have to do re-seek and the access time will increase.
Typical prior art solutions to the problems caused by particle build-up involved removing the optical recording system's housing and disassembling various circuit boards and other hardware to gain physical access to the system's optics and actuator assembly. A brush is then used to sweep the particles off these sensitive components. A test is performed on the unit to verify that it is in proper working condition. Afterwards, the unit is reassembled.
One disadvantage with his process is that it is labor intensive. In addition, the lenses are delicate and physical contact by the brush might damage them. Another disadvantage is the likelihood of accidentally damaging other components of the optical recording system during the disassembling, cleaning, and reassembling process. A further complication is that this process is typically performed at the manufacturer's facilities. As such, the unit has to be packed and shipped. The optical recording system is subject to being damaged during shipping.
One prior art apparatus and method involves implementing a cartridge having one or more brushes. When the cartridge is inserted into the optical recording system, the brushes are placed over and contact the lenses. The optical recording system's spindle motor is used to spin the brushes, thereby cleaning the lenses. Again, this process suffers from the fact that the lenses might be accidentally damaged by the physical contact with the brushes. Also, this implementation does not clean other parts of the optical recording system which are adversely affected by particle build-up, namely the actuator assembly.
Thus, what is needed is an apparatus and method for cleaning various internal components of an optical recording system which is quick, reliable, easy to use, and does not subject the components to being damaged.